package com.touka.filter;

import com.alibaba.fastjson.JSON;
import com.touka.common.BaseContext;
import com.touka.common.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
  // 路径匹配器，支持通配符
  public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

  @Override

  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) servletRequest;
    HttpServletResponse response = (HttpServletResponse) servletResponse;
    // 1. 获取本次请求的URI
    String requestURI = request.getRequestURI();

    // 定义不需要处理的请求的路径
    String[] urls = new String[]{
            "/employee/login",
            "/employee/logout",
            "/backend/**",
            "/front/**",
            "/user/sendMsg",
            "/user/login",
            "/common/upload",
            "/doc.html",
            "/webjars/**",
            "/swagger-resources",
            "/v2/api-docs"
    };

    // 2. 判断本次请求是否需要处理
    boolean check = check(urls, requestURI);
    // 3. 如果不需要处理，则直接放行
    if (check) {
      filterChain.doFilter(request, response);
      return;
    }

    // 4-1. 判断登录状态，如果已登录，则直接放行
    if (request.getSession().getAttribute("employee") != null) {

      BaseContext.setCurrentId((Long) request.getSession().getAttribute("employee")); // 将当前登录用户Id保存到当前线程ThreadLocal中

      filterChain.doFilter(request, response);
      return;
    }

    // 4-2. 判断登录状态，如果已登录，则直接放行
    if (request.getSession().getAttribute("user") != null) {

      BaseContext.setCurrentId((Long) request.getSession().getAttribute("user")); // 将当前登录用户Id保存到当前线程ThreadLocal中

      filterChain.doFilter(request, response);
      return;
    }

    // 5. 如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
    response.getWriter().write(JSON.toJSONString(Result.error("NOTLOGIN")));
  }

  /**
   * 路径匹配，检查本次请求是否需要放行
   *
   * @param urls
   * @param requestURI
   * @return
   */
  public boolean check(String[] urls, String requestURI) {
    for (String url : urls) {
      boolean match = PATH_MATCHER.match(url, requestURI);
      if (match) return true;
    }
    return false;
  }
}
